摘要： 数据加密标准(DES)是Feistel网络型加密算法的实现，但DES的密钥长度较短，不能适应目前网络安全的需求。为此，提出一种DES密钥延长方法，将DES算法的密钥长度由56 bit扩展到112 bit。理论和实例测试结果表明，使用该方法改进后的DES算法加密有效。

关键词: 数据加密标准, 密钥延长, 加密

Abstract: Data Encryption Standard(DES) is a realization of Feistel algorithm, but the length of its key is too short. It can not meet the needs of network security now. Aiming at this problem, this paper proposes a simple method of key extension for the DES. This method extends DES key from 56 bit to 112 bit, and proves its validity by experimental result.

Key words: Data Encryption Standard(DES), key extension, encryption

中图分类号: 

• TP309.2